Daniel Mekonnen1, Aschalew Admassu2, Wondemagegn Mulu3, Aranzazu Amor4, Agustín Benito4, Woynshet Gelaye2, Fantahun Biadglegne3, Bayeh Abera3. 1. Department of Medical Microbiology, Immunology and Parasitology, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia. Electronic address: nigusdaniel@gmail.com. 2. Department of Regional Mycobacteriology Laboratory, Bahir Dar Regional Health Research Laboratory Center, Bahir Dar, Ethiopia. 3. Department of Medical Microbiology, Immunology and Parasitology, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia. 4. National Center of Tropical Medicine, Institute of Health Carlos III, Madrid, Spain.
Abstract
BACKGROUND: The prevalence of multidrug-resistant tuberculosis (TB) among new and retreatment cases in 2011 in Ethiopia was 2.7% and 17.9%, respectively. However, data on heteroresistance and gene mutation profiles of Mycobacterium tuberculosis were not documented. METHODS: A cross-sectional study was conducted on 413 TB-positive clinical specimens submitted between 2012 and 2014 to Bahir Dar Regional Laboratory Center for confirmation of multidrug resistance. Resistance determining genes were analyzed using a line probe assay. RESULTS: Of 413M. tuberculosis isolates, 150 (36.3%) were multidrug-resistant, 19 (4.6%) were resistant only to rifampicin, and 26 (6.3%) were resistant to isoniazid. Of 169 rifampicin-resistant and 176 isoniazid-resistant isolates, only eight (4.7%) showed rifampicin heteroresistance and only two (1.13%) showed isoniazid heteroresistance. Failing of the rpoB WT8 gene with corresponding hybridization of rpoB MUT3 (S531L substitution) accounted for 85 (50.3%) rifampicin-resistant mutations. Among 176 isoniazid-resistant isolates, 155 (88.1%) strains had the Ser315Thr1 substitution. CONCLUSIONS: The prevalence of multidrug-resistant M. tuberculosis was high in the study area. Ser531Leu and Ser315Thr1 substitutions were the highest gene mutations for rifampicin and isoniazid, respectively.
BACKGROUND: The prevalence of multidrug-resistant tuberculosis (TB) among new and retreatment cases in 2011 in Ethiopia was 2.7% and 17.9%, respectively. However, data on heteroresistance and gene mutation profiles of Mycobacterium tuberculosis were not documented. METHODS: A cross-sectional study was conducted on 413 TB-positive clinical specimens submitted between 2012 and 2014 to Bahir Dar Regional Laboratory Center for confirmation of multidrug resistance. Resistance determining genes were analyzed using a line probe assay. RESULTS: Of 413M. tuberculosis isolates, 150 (36.3%) were multidrug-resistant, 19 (4.6%) were resistant only to rifampicin, and 26 (6.3%) were resistant to isoniazid. Of 169 rifampicin-resistant and 176 isoniazid-resistant isolates, only eight (4.7%) showed rifampicin heteroresistance and only two (1.13%) showed isoniazid heteroresistance. Failing of the rpoB WT8 gene with corresponding hybridization of rpoB MUT3 (S531L substitution) accounted for 85 (50.3%) rifampicin-resistant mutations. Among 176 isoniazid-resistant isolates, 155 (88.1%) strains had the Ser315Thr1 substitution. CONCLUSIONS: The prevalence of multidrug-resistant M. tuberculosis was high in the study area. Ser531Leu and Ser315Thr1 substitutions were the highest gene mutations for rifampicin and isoniazid, respectively.
Authors: Soumitesh Chakravorty; Sandy S Roh; Jennifer Glass; Laura E Smith; Ann Marie Simmons; Kevin Lund; Sergey Lokhov; Xin Liu; Peng Xu; Guolong Zhang; Laura E Via; Qingyu Shen; Xianglin Ruan; Xing Yuan; Hong Zhu Zhu; Ekaterina Viazovkina; Shubhada Shenai; Mazhgan Rowneki; Jong Seok Lee; Clifton E Barry; Qian Gao; David Persing; Robert Kwiatkawoski; Martin Jones; Alexander Gall; David Alland Journal: J Clin Microbiol Date: 2016-12-28 Impact factor: 5.948